This project is the continuation and expansion of previous work done on the control of gastrointestinal (GI) bleeding and the passage of alternating current (AC) through tissue. From previous projects, sophisticated computer equipment is available to measure the passage of alternating current through mammalian tissue. Equipment has been developed to measure tissue impedance and phase angle, to modify the wavetrain of the electrosurgical generators, to modify source impedance of the generator and to evaluate both the current and voltage source generators. Alternating current (AC) tissue impedance will be measured and comparisons made between tissues in the gastrointestinal tract. Changes in tissue impedance will be measured with heating and cooling in varying physiological states. Depth of penetration after coagulation will be studied in the canine stomach, with variations of wave form and source impedance. Surgical cutting will be evaluated by its effect on scar formation and the amount of bleeding from a defined electrosurgical incision in the intestine. This should produce less tissue penetration during coagulation and more precise control of bleeding. Preliminary data indicates that physiological parameters of tissue affect alternating current transmission. Impedance and phase angle will be measured over a wide range of frequencies in various tissues. These measurements will be followed by similar measurements after physiological and pathological changes in the gastrointestinal tract. This should supply unique information on the pathology and physiology of the gastrointestinal tract.